The following account of the prior art relates to one of the areas of application of the present application, hearing aids.
A Hearing Instrument (HI) user may have multiple disabilities and therefore shutting the hearing aids down for the night by opening the battery drawer (which is a typical way of powering down a hearing instrument to minimize unnecessary drain of the battery), can be a daily challenge. Alternatively, the user may just leave the hearing instruments in a drawer or on a table, while they are still on, resulting in lower battery life and possibly some feedback noise that might disturb relatives or pets (e.g. during the night).
US 2009/0087005 A1 describes a hearing aid system comprising two hearing aids between which a wireless signal transmission is provided. The hearing aids are automatically switched on and off. To this end, a field strength or value of an electromagnetic signal received by a hearing aid that is transmitted from the respective other hearing aid may be determined. The determined value is compared with a threshold value, the relevant hearing aid being switched off (sleep mode), as long as the field strength is greater than the threshold value and the hearing aid being switched on as long as the measured field strength is lower than the threshold value.
US 2010/0184383 A1 relates to a communication system comprising first and a second communication devices (e.g. a pair of hearing instruments of a binaural hearing aid system), each device comprising transmit and receive units for establishing a wireless link between the devices. At least the first communication device comprises a control unit for dynamically adjusting the transmit power of its transmit unit based on a measure of the quality of the link, wherein the system is adapted to use the dynamic transmit power regulation to implement a partial power-down mode of the system, when the two communication devices are expected NOT to be in a normal use.